diff --git a/c32 b/c32
index e349dfb..7deb54c 100755
--- a/c32
+++ b/c32
@@ -1,7 +1,5 @@
 #!/usr/bin/env sh
 
-cp configure.32.ac configure.ac  && \
-autoconf && \
 ./configure --prefix=/Users/ikarus/.opt CFLAGS=-m32 LDFLAGS=-m32 \
 && make clean \
 && make
diff --git a/c64 b/c64
index 6680cfb..9670212 100755
--- a/c64
+++ b/c64
@@ -1,7 +1,5 @@
 #!/usr/bin/env sh
 
-cp configure.64.ac configure.ac  && \
-autoconf && \
 ./configure CFLAGS="-m64 -g -I/Users/ikarus/.opt64/include" \
   LDFLAGS="-m64 -g -L/Users/ikarus/.opt64/lib" \
 && make clean \
diff --git a/configure b/configure
index b667e86..12f0284 100755
--- a/configure
+++ b/configure
@@ -4479,9 +4479,8 @@ fi
 
 
 
-CFLAGS="$CFLAGS -DNDEBUG -O3 -Wall -m32"
-CCASFLAGS="$CCASFLAGS -m32"
-LDFLAGS="$LDFLAGS -m32"
+
+CFLAGS="$CFLAGS -DNDEBUG -O3 -Wall"
 
 case "$target_os" in
   *linux*)
@@ -4496,7 +4495,6 @@ case "$target_os" in
   esac
 
 
-
 ac_ext=c
 ac_cpp='$CPP $CPPFLAGS'
 ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -5538,12 +5536,6 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
-# remember to enable before release.
-if (test $ac_cv_sizeof_void_p != 4); then
-  { { echo "$as_me:$LINENO: error: Ikarus can only run in 32-bit mode." >&5
-echo "$as_me: error: Ikarus can only run in 32-bit mode." >&2;}
-   { (exit 1); exit 1; }; }
-fi
 
 # Checks for libraries.
 { echo "$as_me:$LINENO: checking for library containing dlsym" >&5
diff --git a/configure.32.ac b/configure.32.ac
deleted file mode 100644
index bcc1cf5..0000000
--- a/configure.32.ac
+++ /dev/null
@@ -1,102 +0,0 @@
-#                                               -*- Autoconf -*-
-# Process this file with autoconf to produce a configure script.
-
-AC_PREREQ(2.59)
-AC_INIT(ikarus, 0.0.3, aghuloum@cs.indiana.edu)
-AC_CANONICAL_SYSTEM
-AM_INIT_AUTOMAKE(ikarus, 0.0.3)
-AC_CONFIG_SRCDIR([src/])
-
-
-AM_PROG_AS
-# Checks for programs.
-AC_PROG_CC
-AM_PROG_CC_C_O
-
-CFLAGS="$CFLAGS -DNDEBUG -O3 -Wall -m32"
-CCASFLAGS="$CCASFLAGS -m32"
-LDFLAGS="$LDFLAGS -m32"
-
-case "$target_os" in
-  *linux*)
-    LDFLAGS="-rdynamic $LDFLAGS"
-    ;;
-  *bsd*)
-    LDFLAGS="-Wl,-E $LDFLAGS"
-    ;;
-  *cygwin*)
-    LDFLAGS="-Wl,-E -Wl,--export-all-symbols $LDFLAGS"
-    ;;
-  esac
-
-
-AC_CHECK_SIZEOF(void *)
-# remember to enable before release.
-if (test $ac_cv_sizeof_void_p != 4); then
-  AC_MSG_ERROR([Ikarus can only run in 32-bit mode.])
-fi
-
-# Checks for libraries.
-AC_SEARCH_LIBS(dlsym, dl,, [AC_MSG_ERROR([Cannot find libdl])])
-AC_SEARCH_LIBS(cos, m,, [AC_MSG_ERROR([Cannot find libm])])
-
-# Checks for header files.
-AC_HEADER_STDC
-AC_HEADER_SYS_WAIT
-
-
-AC_CHECK_HEADERS([assert.h dlfcn.h errno.h fcntl.h signal.h \
-                  stdint.h stdlib.h string.h strings.h \
-                  sys/mman.h sys/resource.h sys/stat.h \
-                  sys/time.h sys/types.h sys/wait.h time.h \
-                  unistd.h])
-
-AC_CHECK_HEADERS([gmp.h],,[AC_MSG_ERROR([
-ERROR: Cannot find libgmp. 
-ERROR: You might want to supply CFLAGS=-I</path/to/include> (containing
-ERROR: the gmp.h header file), and LDFLAGS=-L</path/to/lib> (containing
-ERROR: libgmp.so) if libgmp is installed in a non-standard location.
-ERROR: libgmp can be obtained from <http://gmplib.org>. ])])
-
-# check that gmp is present
-AC_HAVE_LIBRARY([gmp],,[AC_MSG_ERROR([
-ERROR: Cannot find libgmp. 
-ERROR: You might want to supply CFLAGS=-I</path/to/include> (containing
-ERROR: the gmp.h header file), and LDFLAGS=-L</path/to/lib> (containing
-ERROR: libgmp.so) if libgmp is installed in a non-standard location.
-ERROR: libgmp can be obtained from <http://gmplib.org>. ])])
-
-# check that gmp exports mpn_mul
-# unfortunately, gmp.h defines mpn_mul as a macro
-# that expands to __gmpn_mul on my machine.
-AC_CHECK_LIB(gmp,__gmpn_mul,,[AC_MSG_ERROR([
-ERROR: your version of libgmp does not contain a binding for
-ERROR: some of the primitives that ikarus uses.  This is most
-ERROR: likely to happen if your version of gmp was compiled
-ERROR: in 64-bit mode, while ikarus expects needs the 32-bit
-ERROR: version.  Refer to the following bug report for details
-    https://bugs.launchpad.net/ikarus/+bug/159235 
-])])
-
-
-# Checks for typedefs, structures, and compiler characteristics.
-AC_C_CONST
-AC_C_INLINE
-AC_C_RESTRICT
-AC_TYPE_SIZE_T
-AC_HEADER_TIME
-AC_STRUCT_TM
-
-# Checks for library functions.
-AC_FUNC_FORK
-AC_FUNC_MALLOC
-AC_FUNC_MEMCMP
-AC_FUNC_MMAP
-AC_FUNC_STAT
-AC_FUNC_STRFTIME
-AC_FUNC_STRTOD
-AC_CHECK_FUNCS([sigaltstack bzero gettimeofday memmove memset munmap setenv sqrt strerror getaddrinfo])
-AC_CONFIG_HEADERS([config.h])
-AC_CONFIG_FILES(Makefile src/Makefile scheme/Makefile doc/Makefile lib/Makefile benchmarks/Makefile)
-AC_OUTPUT #(Makefile src/Makefile scheme/Makefile doc/Makefile)
-
diff --git a/configure.64.ac b/configure.64.ac
deleted file mode 100644
index 9bb4157..0000000
--- a/configure.64.ac
+++ /dev/null
@@ -1,103 +0,0 @@
-#                                               -*- Autoconf -*-
-# Process this file with autoconf to produce a configure script.
-
-AC_PREREQ(2.59)
-AC_INIT(ikarus, 0.0.3, aghuloum@cs.indiana.edu)
-AC_CANONICAL_SYSTEM
-AM_INIT_AUTOMAKE(ikarus, 0.0.3)
-AC_CONFIG_SRCDIR([src/])
-
-
-AM_PROG_AS
-# Checks for programs.
-AC_PROG_CC
-AM_PROG_CC_C_O
-
-CFLAGS="$CFLAGS -DNDEBUG -O3 -Wall -m64"
-CCASFLAGS="$CCASFLAGS -m64"
-LDFLAGS="$LDFLAGS -m64"
-
-case "$target_os" in
-  *linux*)
-    LDFLAGS="-rdynamic $LDFLAGS"
-    ;;
-  *bsd*)
-    LDFLAGS="-Wl,-E $LDFLAGS"
-    ;;
-  *cygwin*)
-    LDFLAGS="-Wl,-E -Wl,--export-all-symbols $LDFLAGS"
-    ;;
-  esac
-
-
-AC_CHECK_SIZEOF(void *)
-# remember to enable before release.
-# if (test $ac_cv_sizeof_void_p != 4); then
-#   AC_MSG_ERROR([Ikarus can only run in 32-bit mode.])
-# fi
-
-# Checks for libraries.
-AC_SEARCH_LIBS(dlsym, dl,, [AC_MSG_ERROR([Cannot find libdl])])
-AC_SEARCH_LIBS(cos, m,, [AC_MSG_ERROR([Cannot find libm])])
-
-# Checks for header files.
-AC_HEADER_STDC
-AC_HEADER_SYS_WAIT
-
-
-AC_CHECK_HEADERS([assert.h dlfcn.h errno.h fcntl.h signal.h \
-                  stdint.h stdlib.h string.h strings.h \
-                  sys/mman.h sys/resource.h sys/stat.h \
-                  sys/time.h sys/types.h sys/wait.h time.h \
-                  unistd.h])
-
-AC_CHECK_HEADERS([gmp.h],,[AC_MSG_ERROR([
-ERROR: Cannot find libgmp. 
-ERROR: You might want to supply CFLAGS=-I</path/to/include> (containing
-ERROR: the gmp.h header file), and LDFLAGS=-L</path/to/lib> (containing
-ERROR: libgmp.so) if libgmp is installed in a non-standard location.
-ERROR: libgmp can be obtained from <http://gmplib.org>. ])])
-
-# check that gmp is present
-AC_HAVE_LIBRARY([gmp],,[AC_MSG_ERROR([
-ERROR: Cannot find libgmp. 
-ERROR: You might want to supply CFLAGS=-I</path/to/include> (containing
-ERROR: the gmp.h header file), and LDFLAGS=-L</path/to/lib> (containing
-ERROR: libgmp.so) if libgmp is installed in a non-standard location.
-ERROR: libgmp can be obtained from <http://gmplib.org>. ])])
-
-# check that gmp exports mpn_mul
-# unfortunately, gmp.h defines mpn_mul as a macro
-# that expands to __gmpn_mul on my machine.
-
-# AC_CHECK_LIB(gmp,__gmpn_mul,,[AC_MSG_ERROR([
-# ERROR: your version of libgmp does not contain a binding for
-# ERROR: some of the primitives that ikarus uses.  This is most
-# ERROR: likely to happen if your version of gmp was compiled
-# ERROR: in 64-bit mode, while ikarus expects needs the 32-bit
-# ERROR: version.  Refer to the following bug report for details
-#     https://bugs.launchpad.net/ikarus/+bug/159235 
-# ])])
-
-
-# Checks for typedefs, structures, and compiler characteristics.
-AC_C_CONST
-AC_C_INLINE
-AC_C_RESTRICT
-AC_TYPE_SIZE_T
-AC_HEADER_TIME
-AC_STRUCT_TM
-
-# Checks for library functions.
-AC_FUNC_FORK
-AC_FUNC_MALLOC
-AC_FUNC_MEMCMP
-AC_FUNC_MMAP
-AC_FUNC_STAT
-AC_FUNC_STRFTIME
-AC_FUNC_STRTOD
-AC_CHECK_FUNCS([sigaltstack bzero gettimeofday memmove memset munmap setenv sqrt strerror getaddrinfo])
-AC_CONFIG_HEADERS([config.h])
-AC_CONFIG_FILES(Makefile src/Makefile scheme/Makefile doc/Makefile lib/Makefile benchmarks/Makefile)
-AC_OUTPUT #(Makefile src/Makefile scheme/Makefile doc/Makefile)
-
diff --git a/configure.ac b/configure.ac
index bcc1cf5..f159707 100644
--- a/configure.ac
+++ b/configure.ac
@@ -13,9 +13,8 @@ AM_PROG_AS
 AC_PROG_CC
 AM_PROG_CC_C_O
 
-CFLAGS="$CFLAGS -DNDEBUG -O3 -Wall -m32"
-CCASFLAGS="$CCASFLAGS -m32"
-LDFLAGS="$LDFLAGS -m32"
+
+CFLAGS="$CFLAGS -DNDEBUG -O3 -Wall"
 
 case "$target_os" in
   *linux*)
@@ -29,12 +28,7 @@ case "$target_os" in
     ;;
   esac
 
-
 AC_CHECK_SIZEOF(void *)
-# remember to enable before release.
-if (test $ac_cv_sizeof_void_p != 4); then
-  AC_MSG_ERROR([Ikarus can only run in 32-bit mode.])
-fi
 
 # Checks for libraries.
 AC_SEARCH_LIBS(dlsym, dl,, [AC_MSG_ERROR([Cannot find libdl])])
diff --git a/scheme/Makefile.am b/scheme/Makefile.am
index 69abf61..e9b879a 100644
--- a/scheme/Makefile.am
+++ b/scheme/Makefile.am
@@ -1,7 +1,8 @@
 
 nodist_pkglib_DATA=ikarus.boot
 
-EXTRA_DIST=ikarus.boot.prebuilt ikarus.enumerations.ss \
+EXTRA_DIST=ikarus.boot.4.prebuilt ikarus.boot.8.prebuilt \
+  ikarus.enumerations.ss \
   ikarus.exceptions.ss ikarus.apply.ss ikarus.bytevectors.ss \
   ikarus.cafe.ss ikarus.chars.ss ikarus.code-objects.ss \
   ikarus.codecs.ss ikarus.collect.ss ikarus.command-line.ss \
@@ -33,16 +34,18 @@ revno = "$(shell sed 's/ .*//' ../.bzr/branch/last-revision 2>/dev/null)"
 last-revision: $(shell ls ../.bzr/branch/last-revision 2>/dev/null) 
 	echo $(revno) >$@
 
+sizeofvoidp = $(shell grep SIZEOF_VOID_P ../config.h | sed "s/.*\(.\)/\1/g")
+
 ikarus.config.ss: Makefile last-revision ../config.h
 	echo '(define ikarus-version "$(PACKAGE_VERSION)")' >$@
 	echo '(define ikarus-revision "$(shell cat last-revision)")' >>$@
 	echo '(define ikarus-lib-dir "$(pkglibdir)")' >>$@
-	echo '(define wordsize $(shell grep SIZEOF_VOID_P ../config.h | sed "s/.*\(.\)/\1/g"))' >>$@
+	echo '(define wordsize $(sizeofvoidp))' >>$@
 
 
 CLEANFILES=$(nodist_pkglib_DATA) ikarus.config.ss
 MAINTAINERCLEANFILES=last-revision
 
 ikarus.boot: $(EXTRA_DIST) ikarus.config.ss
-	../src/ikarus -b ./ikarus.boot.prebuilt --r6rs-script makefile.ss
+	../src/ikarus -b ./ikarus.boot.$(sizeofvoidp).prebuilt --r6rs-script makefile.ss
 
diff --git a/scheme/Makefile.in b/scheme/Makefile.in
index cf26200..a60dba7 100644
--- a/scheme/Makefile.in
+++ b/scheme/Makefile.in
@@ -155,7 +155,8 @@ target_vendor = @target_vendor@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 nodist_pkglib_DATA = ikarus.boot
-EXTRA_DIST = ikarus.boot.prebuilt ikarus.enumerations.ss \
+EXTRA_DIST = ikarus.boot.4.prebuilt ikarus.boot.8.prebuilt \
+  ikarus.enumerations.ss \
   ikarus.exceptions.ss ikarus.apply.ss ikarus.bytevectors.ss \
   ikarus.cafe.ss ikarus.chars.ss ikarus.code-objects.ss \
   ikarus.codecs.ss ikarus.collect.ss ikarus.command-line.ss \
@@ -182,6 +183,7 @@ EXTRA_DIST = ikarus.boot.prebuilt ikarus.enumerations.ss \
   ikarus.compiler.tag-annotation-analysis.ss ikarus.ontology.ss
 
 revno = "$(shell sed 's/ .*//' ../.bzr/branch/last-revision 2>/dev/null)"
+sizeofvoidp = $(shell grep SIZEOF_VOID_P ../config.h | sed "s/.*\(.\)/\1/g")
 CLEANFILES = $(nodist_pkglib_DATA) ikarus.config.ss
 MAINTAINERCLEANFILES = last-revision
 all: all-am
@@ -376,10 +378,10 @@ ikarus.config.ss: Makefile last-revision ../config.h
 	echo '(define ikarus-version "$(PACKAGE_VERSION)")' >$@
 	echo '(define ikarus-revision "$(shell cat last-revision)")' >>$@
 	echo '(define ikarus-lib-dir "$(pkglibdir)")' >>$@
-	echo '(define wordsize $(shell grep SIZEOF_VOID_P ../config.h | sed "s/.*\(.\)/\1/g"))' >>$@
+	echo '(define wordsize $(sizeofvoidp))' >>$@
 
 ikarus.boot: $(EXTRA_DIST) ikarus.config.ss
-	../src/ikarus -b ./ikarus.boot.prebuilt --r6rs-script makefile.ss
+	../src/ikarus -b ./ikarus.boot.$(sizeofvoidp).prebuilt --r6rs-script makefile.ss
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
 # Otherwise a system limit (for SysV at least) may be exceeded.
 .NOEXPORT:
diff --git a/scheme/ikarus.boot.prebuilt b/scheme/ikarus.boot.4.prebuilt
similarity index 100%
rename from scheme/ikarus.boot.prebuilt
rename to scheme/ikarus.boot.4.prebuilt
diff --git a/scheme/ikarus.boot.8.prebuilt b/scheme/ikarus.boot.8.prebuilt
new file mode 100644
index 0000000..74ce23c
Binary files /dev/null and b/scheme/ikarus.boot.8.prebuilt differ
diff --git a/scheme/last-revision b/scheme/last-revision
index 47702a2..e19b378 100644
--- a/scheme/last-revision
+++ b/scheme/last-revision
@@ -1 +1 @@
-1545
+1546